Turbine aggregate comprising an ahead turbine and an astern turbine



W. ANDERHUB July 2, 1929.

TURBINE AGGREGATE COMPRIS ING AN AHEAD TURBINE AND AN ASTERN TURBINE Filed July 23, 1923 Patented July 2, 1929 WALTER ANDERHUB, 0F ZURICH, SWITZERLAND.

TTIIRBINEAGGREGATIE ooiurnrsmo AHEAD TURBINE AND AN astrnnn TURBINE.

Application fileclJuly 2a, 1923, Serial No. 653,293, and in Switzerland August 4, 1922.

The invention relates to improvements in steam turbine aggregates comprising i an ahead turbine and an astern turbine.

It is a known fact that the economical utilization oi the steam in the last stages of steam turbines that have to deal with large quantities of steam presents diliieulties as the length of the blades and the diameter of the rotor respectively cannot be chosentoo large owing to the strength of the material employed. In order to overcome these difliculties it has already beenproposed to subdivide the stream of steam leaving a low pres sure stage of a steam turbine into portions and to utilize these in separate runner wheels. Such an arrangement, however, requires an essential lengthening of the steam turbine. This is a serious drawback especially in such cases where the turbines have to be arranged in a limited space, as is for instance the case with steam turbine driven locomotives, on which besides the ahead turbine an astern turbine has to be arranged within the given clearance gauge. lVith vehicles of this type the ahead turbine and the astern turbine are preferably arranged to both sides of the iongitudinal axis and transverse to the latter. The arrangement oi the comparatively short astern turbine does not present any diiliculty, whereas the substantially longer ahead turbine can only belodgedwith great di'lhculties within the available limited space. In order to overcome this diflicultyin locomotives, l have constructed a turbine aggregate comprising an ahead turbine and an ast-ern turbine contained in separate casings and. in which the steam is subdivided in front oi at least the last stage oi the ahead turbine into two portions that are caused to work in dirt? ferent runner wheels, shows according to the present invention the feature that those runner wheels of the ahead turbine to which one of said portions is supplied arearranged witlnn the casing of the astern turbine. By

this means the ahead turbine is not appreciably longer than the ahead turbine 01 an aggregate of the ordinary type in which the quantity of steam is not subdivided, and the lengths of the blades remain within reasonable limits owing to the subdivision of the steam.

Preferably the last runner wheel of the astern turbine and the last runner wheel of the portion of the ahead turbine arranged in the casing ofthe astern turbine discharge into an exhaust space common to both wheels. A constructional example of the subject matter of the present invention is illustrated an inlet branch 1 and an outlet branch 5;

The astcrn turbine 2 is contained in a using 13 having an inlet branch 6 and an outlet branch 7. The quantity of steam leaving the last but one stage of the ahead turbine 1 is subdivided into two portions of which the one is supplied to a runner wheel 9 while the rest is conducted by means of a pipe 11 to a runner wheel 12 situated in the casing 13 of the astern, turbine. The runner wheel 12 of the forward driving turbine and the last runner wheel 14. of the astern or reversing turbine discharge into an exhaust space 15 common to both. The runner wheels 9 and 12 form together the last stage of the ahead turbine 1.

Preferably a shut-off valve 17 inserted in the pipe 11 to provide that when the ahead turbine 1 runs under partial loads, in which case the efficiency of the last stage low, all the steam supplied to the runner wheel 9 113011 a closing of the shut-oil valve, the W me]. 9 Working then alsowith a comparatively good etiiciency.

Claims:

1. A turbine aggregate for locomotives, comprising an ahead turbine having a casing and a plurality of runner wheels, an astern turbine having a separate casing and a runner wheel of the ahead. turbine inclosed in said separate casing, a shaft common to both turbines, means on said shaft between the turbines to transmit power to the locomotive, and a pipe communicating with a space in the ahead turbine situated in front of the last stage of said turbine and conducting a portion of the steam from said. space to the runner wheel which is arranged within the casing of the astern turbine, the last mentioned runner wheel working in parallel with the runner wheels arranged within the ahead turbine that are impinged by the portion of the steam that remains in the ahead turbine.

2. A turbine aggregate for locomotives, comprising an ahead turbine having a casing and a plurality of runner wheels, an astern turbine having a separate casing and a runner wheel of the ahead turbine inclosed in'said separate casing, a shaft common to ranged within the ahead turbine that are impinged by the portion ofthe steam that remains'in the ahead turbine, and a shut-01f member inserted in said conduit pipe permitting a cutting off of the runner wheel arranged within the casing of the astern turbine when the ahead turbine runs under partialloads. V

3 A turbine aggregate for locomotives, comprising an ahead turbine having a casing and a plurality of runner wheels, an 'astern turbine having a separate casing and enclosing a runner wheel of the ahead'turbine, said runner wheel having an exhaust space common with the aster-n turbine, a

shaft common to both turbines, a pinion on said shaft, between the turbines, to transmit power to the locomotive and a pipe communicating with a space in the ahead turbine situated in front of the last stage of said turbine and conducting a portion of the steam from said space to the runner wheel which is arranged within the casing of the astern turbine, the last mentioned runner wheel working in parallel with the runnerwheels arranged Within the ahead turbine that are impinged by the portion of the steam that remains in the ahead turbine.

' 4:. A turbine aggregate. comprising an ahead turbine having a casing and a plural ity of runner wheels therein, a reversing turbine consisting of a separate casingand a plurality of runner wheels therein one of which operates with the ahead turbine, 21

shaft common to both casings and all runner Wheels, a pinion on said shaft between the casings, and a pipe communicating with a space in the ahead turbine in front of the last stage of said turbine and conducting a portion of the steam from said space directly to the runner wheel in the casing of the re versing turbine working with the runner wheels in the ahead turbine.

5. A turbine aggregate for locomotives, comprising a multistage ahead turbine having a casing and a plurality of runner wheels, an astern turbine having a separate casing enclosing runner wheels for backward running, the last stage of the ahead turbine being subdivided into two halves of which the one is arranged in the casing of the ahead turbine and the other in the casing of the astern. turbine, a shaft to which are lixed all the said runner wheels, and a conduit for supplying a portion of the steam from a space in front of the stages of the ahead turbine subdivided into two halves to the runner wheels of the half arranged in the asiern turbine and working in parallel with the other half of said runner wheels arranged in the ahead turbine and impinged by the other portion of the steam.

6. A turbine aggregate for locomotives comprising a turbine for for ard running having a casing and a plurality of runner wheels, a pipe for supplying live steam to said turbine, a turbine for backward rnnning having a separate casing, a pipe for supplying live steam to said turbine for back ward running, one runner wheel of the last stage of the turbine for forward running inclosed in said separate casing, a shaft common to both turbines, means on said, shaft between the turbines to transmit power to the locomotive, and a pipe communicating with a space in the turbine for forward running situated in front of the last stage of said turbine and conducting a portion of the low pressure steam from said space to the runner wheel which is arranged within the easing of the turbine for the b=urkward running, the last mentioned runner wheel working in parallel with the runner wheels arranged within the turbine for forwzurd running that are impinged by the portion of the low pressure steam that remains in the turbine f or forward running.

In testimony whereof I afiix my signature.

lVALTER ANDEBHUB.

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